Rolamite scale construction

ABSTRACT

There is disclosed a bathroom scale comprising a base member, a platform member mounted for free vertical movement relative to the base member, a flexible Rolamite band located between the platform member and the base member, transfer means connected to the base member and adapted to transfer a load imposed upon the platform to the roller band wherein the load on the platform causes a movement of the roller band indicative of the weight of the load, and an indicator operably connected to the Rolamite band indicating the weight of the load.

United States Patent Cooley [4 1 Mar. 28, 1972 [54] ROLAMITE SCALECONSTRUCTION 1,123,734 6/1956 France ..177/DlG. 9 r 1,449,206 7/1966France ..l77/DlG. 9 [72] memo" Cmley Chlcag 151,626 1922 Great Britain..177/230 [73] Assignee: The Borg-Erickson Corporation, Chicago,

Primary Examiner-Robert S. Ward, Jr. [22] Filed: Jan. 8, 1970Attorney-Hume, Clement, Hume & Lee

[2]] Appl. No.: 1,414 [57] ABSTRACT 521 ms. (:1 ..177/230, 177/234,177/1310. 9 is dimmed a scale E 3 [511 1111.01 ..G0lg 3/08, G01 g 21/02,GOlg 23/26 member .Platfmm membe' mmmted [58] Fltld 61 Search ..177/230,234, 225, DIG. 9 I lame the base membe" a flex'ble band located betweenthe platform member and the base member, 56] R f gnce Ci d transfermeans connected to the base member and adapted to transfer a loadimposed upon the platform to the roller band UNITED STATES PATENTSwherein the load on the platform causes a movement of the 2,098,84511/1937 Weber et al ..'....177/234 x roller band indicative of theWeight of the load, and an 3,084,755 4/1963 K i 177/230 tor operablyconnected to the Rolamite band indicating the 3,405,775 10/1968 Grady etal. .....177/23o x weight ofthe load- 2,622,938 12/1952 Van Duyn..l77/DlG. 9.

20 Claims, 6 Drawing Figures BACKGROUND OF THE INVENTION I The presentinvention relates to weighing scales and, more particularly, to bathroomscales comprising the Rolamite principle.

A great number of bathroom scales are now available and the pricesthereof range from a few dollars to substantial sums of money. To someextent, the accuracy of the scale is related to the price chargedtherefor. Most of the scales, however, and particularly those that arelow priced, have a considerable degree of error and further, preciseindication of the magnitude of any given weight may vary from day to daywith the same scale. It has also been found that different samples ofthe same model will provide different weight indications for a givenpredetermined weight. Theuser of these scales then cannot expect greataccuracy and must also appreciate that the margin of error is variableand may shift from day to day.

One of the important limitations in the less expensive bathroom scalesis that in the less expensive models the platform and its support leversthat transfer a weight imposed upon the platform to an indicator dialare relatively unstable and a fair degree of accuracy in the weightindication can be obtained only when the weight is properly centered onthe platform. Such centering of the weight cannot be expected whenpersons using the scales step on and off hurriedly and do not understandthat their weight should be properly centered on the platform. As aresult, off-center loading and any tilting of the platform as a resultof improper position of the load will cause binding and inaccuracy inthe weight indications.

Another problem in obtaining accurate weight indications is that theforce transmitted by the platform is normally directed to a spring andas the spring ages from continuous use, the inherent force transmittedfrom the spring to the readout dial varies, and this variation destroysthe accuracy of the scale. By utilizing the Rolamite principle in abathroom scale, there above limitations may be eliminated. The Rolamiteprinciple is a mechanical design concept developed by the SandiaLaboratory in Albuquerque, New Mexico. The principle is completely.described in a research report available from the National Bureau ofStandards, United States Department of Commerce entitled Rolamite: A NewMechanical Design Concept" Research Report No. SC-RR-67-656A, which waspublished in December of 1967 by the Sandia Laboratory of Albuquerque,New Mexico.

This principle is also described in three United States Patents grantedto Donald F. Wilkes and assigned to the United States Atomic EnergyCommission, US. Pat. Nos. 3,452,175 issued June 24, I969; 3,452,309issued June 24, 1969; and 3,471,668 issued October 7, 19 69.

The Rolamite principle utilizes a roller band device which substantiallyeliminates or minimizes sliding friction. In addition, Rolamite devicesare easily microminiaturized and are extremely tolerant of productionvariations.

The basic Rolamite geometry comprises two rolling elements insideparallel guide surfaces, locked in a free rolling, counter-rotatingcluster by the elastic constraints of an entwined flexible metallic bandunder tension. This geometry ensures that the motion of the rollerrelative to the guide surfaces is accomplished by rolling, not sliding.The Rolamite principle approaches pure rolling in .a much closer mannerthan the other types of bearings and does not require lubrication. Thisprinciple will be better understood in conjunction with the disclosedembodiment and further details may be obtained by referring to the abovementioned references.

SUMMARY OF THE INVENTION The general purpose of this invention is toprovide a bathroom scale which embraces all of the advantages ofsimilarly employed scales and possesses none of the aforedescribedlimitations. To attain this, the present invention contemplates theutilization of the Rolamite principle in a bathroom scale to provide ameans for transferring the weight from a platform to a calibrated dialwithout encountering appreciable friction. Moreover,-the Rolamite bandis utilized to provide a calibrated force to enable an accurate readouton an indicator scale.

The bathroom scale of the present invention comprises a base member anda platform member mounted for free vertical movement relative to thebase member. A ball screw and nut are located between the platform andthe base and are adapted to convert the vertical movement of theplatfon'n in response to a load being placed upon it to an axial force.A quadrant lever is rotatably connected to the ball nut and is operablein response to the axial force from the ball nut. A first rotatablemember is connected between the base and the platform. A secondrotatable member is operably connected between the base and the platformand is adjacent to the first rotatable member. A flexible roller bandhaving its ends secured to the quadrant lever is looped in a generallyS-shaped fashion about the first and second rotatable members. Lastly,an indicator is connected to the second rotatable member for giving areadout of the weight on tlie'platform. When a weight is applied to thescale platform, the ball nut rotates and provides a torsional forcethrough the quadrant lever. This force is transmitted to the Rolamiteband, thereby producing a second force in opposition to the torsionalforce and, as these two opposing forces reach a state of equilibrium,the indicator comes to rest showing the weight that is placed upon theplatform.

It is therefore an object of the present invention to provide a weighingdevice particularly useful as a bathroom scale that provides muchgreater accuracy than the scales now available.

Another object is to provide a bathroom scale that is relativelyinexpensive.

A further object is to provide a bathroom scale where an off-centerimposition of the load upon the platform will not substantially affectthe accuracy of the weight indication provided by the scale.

Still another object is to provide a means in a bathroom scale toaccurately calibrated a readout dial so that the proper weight may beindicated.

Yet another object is to provide a bathroom scale that is small andcompact and presents a thin and attractive sil houette.

A still further object is to the Rolamite principle. g

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings.

provide a bathroom scale utilizing BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a top view of the scale.

FIG. 2 is a side view of the scale taken along the lines 2-2 of FIG. 1.s

FIG. 3 is an enlarged orthogonal view of the mechanism utilized in thescale of FIG. 1.

FIG. 4 is a cross-sectional view taken along the lines 4-4 of FIG. 3.

FIG. 5 is atop view, partly in section, of the Rolamite band utilized inFIG. 3.

FIG. 6 is a cross-sectional view of the Rolamite band shown in FIG. 5taken along the lines 6-6.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingswherein like reference characters designate like or corresponding partsthroughout the several views, there is shown in FIG. 1 a scale 10.Broadly, the scale 10 comprises a weighing platform 12 mounted upon abase 14 (FIG. 2) for free vertical movement relative to the base. Theplatform is stabilized by a plurality of linear ball bearing alignmentpins 18 and rests upon a ball screw 20. Attached to the ball screw 20 isa quadrant lever 30 which is operably connected to an indicator 15.

Referring now to FIG. 2 and FIG. 3 which constitute the preferredembodiment of Rolamite Scale 10, it can be seen that platform 12 ismounted upon base 14 and rests upon a ball screw 20. The ball screw 20function as a stationary stud. A nut 21, which may be of thenon-circulating variety, is in operable engagement with ball screw 20and is used to convert the downward motion of the platform into atorsional force. While a ball screw and nut are illustrated, anysuitable force transfer means may be utilized. Located within platform12 is an indicator 15. The indicator comprises a window 13 through whichcan be seen the readout dial 16 and an indicator dial hand 17. Indicatordial hand 17 is connected to a shaft 52. Shaft 52 is connected to aroller 50. Roller 50 is rotatably connected to base 14 by a suitableconnection means 51. To facilitate the rotation of shaft 52, a lowfriction bearing 54 may be interposed between shaft 52 and connecting51. A second roller 40 is rotatably mounted by suitable connecting means41 adjacent to roller 50. It will be noted that the diameter of roller40 is greater than the diameter of roller 50. Roller 40 is mounted upona shaft 42 and rotates freely.

Connected to ball nut 21 is a quadrant lever 30. Quadrant lever 30 isgenerally planar but contains downwardly protruding ribs 34, 36 and 38.Ball screw 20 functions as a stationary stud mounted to base section 14of the scale. When a load is placed upon platform 12, the platform movesdownwardly. This force is transmitted to a ball thrust bearing 22 to aball screw 20 thereby causing ball nut 21 to rotate. This rotationtransmits the downward force of the load into a torsional force andthereby causing quadrant lever 30 to rotate as shown in FIG. 3. As willbe explained below, this causes roller 50 to rotate, thereby rotatingroller band 60 which then causes indicator dial hand 17 to also rotate.

Referring to FIG. 3, the solid lines show quadrant lever 30 in itsposition when no load is applied to the platform. The dotted lines tothe right shown the deflection of quadrant lever 30 now designated as 30when a weight is placed upon the platform. A slip fit key 24 may beprovided between ball nut 21 and quadrant lever 30 to facilitate thefree axial movement between the outer diameters of the ball nut 21 andthe quadrant lever 30.

Lastly, a thin flexible band 60 is utilized to functionally linktogether quadrant lever 30 and rollers 40 and 50. Flexible roller band60, sometimes referred to as a Rolamite band, comprises a flexiblematerial and, in a preferred embodiment, comprises a hardened springtempered steel. It will be recognized that other flexible materials suchas plastic may also be utilized without departing from the scope of theinvention. Referring to FIGS. and 6, it can be seen that roller band 60comprises a first surface 61 and a second surface 63. Along the firstsurface, a tapered, depressed segment is placed. One such manner ofcausing this depressed segment is to chemically mill the surface of theband. Preferably, the shape of the depressed segment has a taperedcross-sectional area. After chemically milling the band, a small ridge73 remains on each side of the depressed segment. It will be recognizedby one skilled in the art that rather than using a depressed segmenthaving a tapered cross-sectional area, band 60 may be formed by a thinflexible band having a tapered cross-sectional area along its entirety.If there were no tapering, roller band 60 would then function as aconstant force spring and could not be utilized to calibrate indicator15.

After milling the band 60, the band 60 must be preformed in order toenable a tension force to be present when it is fastened to the quadrantlever 30. This performing requires that the band be shaped into acircular configuration wherein the first surface 61 of the band 60,having the depressed segment forms the inner surface of the prestressedband. It is necessary that the prestress radius of the band be smallerthan the radius of the ridge 34 of the quadrant lever 30. For example,in an exemplary embodiment, if the ridge 34 had a radius of 5 inchesthen the band 60 would be preformed into a circular configuration havinga radius of approximately 3 3/16 inches. This performing will enable theband 60 to follow the contour of the ridge 34 of the quadrant lever 30as shown in FIG. 3.

Referring again to FIG. 3, it can be seen that after performing the band60, a first end 67 is fastened to the ridge 34 of the quadrant lever 30.The roller band 60 is looped in a generally S-shaped fashion aboutroller 50 and roller 40 and is then fastened to ridge 36 of quadrantlever 30. A second end 67 of the band 60 is fastened to the ridge 36 ofquadrant lever 30. In placing the roller band 60, it is important toinsure that the first surface 61 is in contact with roller 50 and thatroller 50 is able to physically engage the depressed segment 66.

The operation of scale 10 will now be explained with referenceparticularly to FIGS. 2 and 3. When a load is placed upon platform 12,the platform moves downwardly. Ball screw 20 functions as a stationarystud mounted on base section 14. However, ball nut 21 rotates therebycausing a torsional force upon quadrant lever 30. Quadrant lever 30thereby rotates clockwise in response to the force. It will be readilyrecognized that the direction ofrotation is unimportant and that byutilizing an oppositely threaded ball screw, the direction of rotationcould be reversed. Slit 32 in quadrant lever 30 allows the quadrantlever to pass over rollers 40 and 50 without interfering with theirrotation. The movement of quadrant lever 30 causes a rolling movement ofroller band 60 as explained in the Wilkes patents. This rolling movementof roller band 60 causes roller 50 to rotate thereby rotating shaft 52and indicator dial hand 17. The force produced by roller band 60 inconjunction with the Rolamite principle causes a torque which isopposite in direction to the torque produced by quadrant lever 30. Whenthese two torques reach a point of equilibrium, the indicating dial hand17 stops moving and the weight of the load may be read on readout dial16. When the load is removed, the forces present are released and thedial returns to zero and quadrant lever 30 returns to its originalposition.

Depending upon the weight applied, the rotation of quadrant lever 30 andthe subsequent force created by roller band 60 varies. The variation ofthis force is determined by a portion of the depressed segment 66 whichis in operable engagement with roller 50. For example, when the portionof roller band designated as 68 in FIGS. 5 is in contact with roller 50at the twelve oclock position, this may indicate 300 pounds of pressureon the platform 12. If point 70 of FIG. 5 were in the twelve oclockposition with relation to roller 50, this would indicate approximately15 pounds of pressure on the platform. Likewise, if point 72 were incontact with the twelve o'clock position of roller 50 then this would beindicative of zero weight on platform 12. It can be seen that since thedepressed segment 66 is tapered any intermediate weight between 15 and300 pounds could also be registered. As explained in the Wilkes patents,and in the Sandia Laboratory article, the depressed segment 66 of rollerband 60 causes the variation in forces depending upon thecross-sectional area of the depressed segment. The force produced byroller band 60 varies inversely with the cross-sectional area of thedepressed segment 66. It will also be recognized by one skilled in theart that a force is only produced by roller band 60 when the two rollersaround which it is looped are of differing diameters. For properoperation, the diameter of roller 50 must be less than the diameter ofroller 40. Formulas for computing the various forces required dependingupon thelength of the band utilized and the material utilized may befound in the Sandia Laboratory report.

One specific embodiment of the Rolamite scale 10 may employ thefollowing exemplary dimensions and material but if will be recognized byone skilled in the art that many modifications may be made thereinwithout departing from the scope of the invention. All dimensions are ininches unless otherwise indicated:

Diameter of Roller 40 L992 Diameter of Roller 50 1.242

Radius of Rib 34 5.000

Radius of Rib 36 2.875

Radius of Slit 32 4.375

Length of Roller Band 60 15.054 approx. Width of Roller Band 60 L000Thickness of Roller Band 60 7 0.0085

Depth of depressed segment 66 0.0065

Width of Rib 73 0.030

Length of depressed segment 66 Reference Point 68 to Reference Point 703.731 Reference Point 68 to Reference Point 72 3.927 Reference Point 72to Reference Point 74 8.334 approx. Modulus of Elasticity of Roller Band60 30 x In summary, therefore, the Rolamite principle is utilized toprovide a frictionless means for creating a force created by roller band60 which opposes the force setup in ball screw by a load being placedupon the scale platform 12. When the weight is placed upon platform 12,this pushes ball nut 21 down thereby converting the downward force onthe platform 12 to a torsional force and thereby rotating quadrant leverin a clockwise direction. This force then causes roller band 60 to movefrictionlessly and create a force which opposes the force beingtransmitted by the quadrant lever 30. The movement of roller band alsodrives dial hand 17 over the readout dial l6 and as the force created byroller band 60 reaches a state of equilibrium with the force transmittedby ball screw 20 through quadrant lever 30, the indicating dial hand 17comes to rest over a line on dial 16 indicating the weight.

it should be understood, of course, that the foregoing disclosurerelates only to a preferred embodiment of the invention and thatnumerous modifications or alterations may be made therein withoutdeparting from the spirit and the scope of the invention as set forth inthe appended claims. What is claimed is:

l. A bathroom scale comprising:

a base member;

a platform member mounted for free vertical movement relative to saidbase member;

a flexible roller band between said platform member and said base memberwherein the surface of said roller band comprises a taperedcross-sectional area;

transfer means connected to said base member and adapted to transfer aload imposed upon said platform to said roller band wherein said load onsaid platform causes a movement of said roller band indicative of theweight of said load; and

indicator means operably connected to said roller band for indicatingsaid weight of said load.

2. A bathroom scale comprising:

a base member;

a platform member mounted for free vertical movement relative to saidbase member;

a flexible roller hand between said platform member and said base memberwherein said roller band comprises a depressed segment having a taperedcross-sectional area;

transfer means connected to said base member and adapted to transfer aload imposed upon said platform to said roller band wherein said load onsaid platform causes a movement of said roller band indicative of theweight of said load; and

indicator means operably connected to said roller band for indicatingsaid weight of said load.

3. The bathroom scale of claim 2 wherein said transfer means comprises:

a first member adapted to convert said vertical movement of saidplatform to a torsional force in response to said load on said platform;and

lever means rotatably connected to said first member and operable inresponse to said torsional force to impart a rolling movement to saidroller band.

4. The bathroom scale of claim 3 wherein said first and second ends ofsaid roller band are secured to said lever means.

5. The bathroom scale of claim 4 further comprising a second rotatablemember adjacent to said indicator means wherein said roller band islooped in a generally S-shaped fashion around said second rotatablemember and said indicator means, said tapered cross-sectional segment ofsaid roller band being operably engaged with said indicator means andsaid second rotatable member to produce a second force in opposition tosaid torsional force.

6. The-bathroom scale of claim 5 wherein said second force created bysaid roller band varies inversely to the cross-sectional area of saidtapered segment of said roller band which is in operable engagement withsaid indicator means.

7. The bathroom scale of claim 6 wherein said cross-sectional area ofsaid depressed segment of said roller band which is in operableengagement with said indicator means comprises a uniform cross-sectionalarea when said load is removed from said platform.

8. The bathroom scale of claim 7 wherein said roller band comprises aflexible steel band,

9. The bathroom scale of claim 7 wherein said roller band comprises aflexible plastic band.

10. The bathroom scale of claim 8 wherein said depressed segment isfonned by chemically milling said surface of said roller band.

11. A bathroom scale comprising:

a base member;

a platform member mounted for free vertical movement relative to saidbase member;

a first member operably connected between said platform and said base,said first member being adapted to convert said vertical movement ofsaid platform to a torsional force in response to a load placed thereon;

a lever means rotatably connected to said first member and operable inresponse to said torsional force;

a second rotatable member operably connected between said base and saidplatform;

a third rotatable member operably. connected between said base and saidplatform, said third rotatable member being positioned adjacent to saidsecond rotatable member;

a flexible roller band having a first end and a second end, said firstand second ends being secured to said lever means and wherein saidroller band is looped in a generally S-shaped fashion about said secondand third rotatable members; and I indicator means rotatably connectedto said third rotatable member for indicating the weight of said loadwherein movement of said lever means in response to said torsional forcecauses a rolling movement of said roller band thereby producing a secondforce in opposition to said torsional force and wherein said secondforce produces rotation of said indicator means.

12. The bathroom scale of claim 11 wherein said roller band comprises adepressed segment having a tapered cross-sectional area wherein saidsecond force created by said roller band varies inversely to thecross-sectional area ofv said segment which is in operable engagementwith said third rotatable member, said second force being indicative ofsaid load on said platform and wherein the movement of said rolling bandthereby causes the rotation of said third rotatable member.

13. The bathroom scale of claim 12 wherein the diameter of said secondrotatable member is greater than the diameter of said third rotatablemember.

14. The bathroom scale of claim 13 wherein said first member comprisesaball screw and nut.

15. The bathroom scale of claim 14 wherein said roller band comprises aflexible steel band.

16. A bathroom scale comprising:

a base member;

a platform member mounted for free vertical movement relative to saidbase member;

a ball screw and nut operably connected between said platform and saidbase, said ball screw and nut being adapted to convert said verticalmovement of said platform to a torsional force in response to a loadplaced thereon;

a lever means rotatably connected to said nut and operable in responseto said torsional force;

a first rotatable member operably connected between said base and saidplatform;

a second rotatable member having a diameter smaller than the diameter ofsaid first rotatable member operably connected between said base andsaid platform, said second rotatable member being positioned adjacent tosaid first rotatable member;

a flexible steel roller band having a first end and a second end, saidfirst and second ends being secured to said lever means and wherein saidroller band is looped in a generally S-shaped fashion about said firstand second rotatable members, said roller band comprising a depressedsegment having a tapered cross-sectional area; and

Indicator means rotatably connected to said second rotatable member forindicating the weight of said load wherein movement of said lever meansin response to said torsional force causes a rolling movement of saidroller band thereby producing a second force in opposition to saidtorsional force, said second force producing a rotation of saidindicator means and wherein the amount of said rotation of saidindicator means corresponds to the weight of said load and is determinedby the cross-sectional area of said segment which is in operableengagement with said second rotatable member.

17. A bathroom scale comprising:

a base member;

a platform member mounted for movement relative to said base member;

a plurality of adjacent rotatable members located between said platformmember and said base member;

a guide means for guiding the rotation of said rotatable members;

a flexible roller band looped under tension in a general 8- shapedfashion about said rotatable members;

transfer means adapted to transfer a load imposed upon said platformmember to said roller band thereby causing a substantially frictionlessmovement of said roller band wherein said movement is indicative of theweight of said load; and

indicator means operably connected to said roller band for indicatingsaid weight of said load.

18. The bathroom scale of claim 17 wherein a portion of said flexibleroller band is fastened to said transfer means.

19. The bathroom scale of claim 18 wherein said guide means are locatedin said transfer means.

20. The bathroom scale of claim 19 wherein said transfer meanscomprises:

a ball screw and nut operably connected between said platform member andsaid base member, said ball screw and nut being adapted to convert saidmovement of said platform to a torsional force in response to a loadplaced thereon; and

a lever means rotatably connected to said nut and operable in responseto said torsional force to cause said movement of said roller band.

1. A bathroom scale comprising: a base member; a platform member mountedfor free vertical movement relative to said base member; a flexibleroller band between said platform member and said base member whereinthE surface of said roller band comprises a tapered cross-sectionalarea; transfer means connected to said base member and adapted totransfer a load imposed upon said platform to said roller band whereinsaid load on said platform causes a movement of said roller bandindicative of the weight of said load; and indicator means operablyconnected to said roller band for indicating said weight of said load.2. A bathroom scale comprising: a base member; a platform member mountedfor free vertical movement relative to said base member; a flexibleroller band between said platform member and said base member whereinsaid roller band comprises a depressed segment having a taperedcross-sectional area; transfer means connected to said base member andadapted to transfer a load imposed upon said platform to said rollerband wherein said load on said platform causes a movement of said rollerband indicative of the weight of said load; and indicator means operablyconnected to said roller band for indicating said weight of said load.3. The bathroom scale of claim 2 wherein said transfer means comprises:a first member adapted to convert said vertical movement of saidplatform to a torsional force in response to said load on said platform;and lever means rotatably connected to said first member and operable inresponse to said torsional force to impart a rolling movement to saidroller band.
 4. The bathroom scale of claim 3 wherein said first andsecond ends of said roller band are secured to said lever means.
 5. Thebathroom scale of claim 4 further comprising a second rotatable memberadjacent to said indicator means wherein said roller band is looped in agenerally S-shaped fashion around said second rotatable member and saidindicator means, said tapered cross-sectional segment of said rollerband being operably engaged with said indicator means and said secondrotatable member to produce a second force in opposition to saidtorsional force.
 6. The bathroom scale of claim 5 wherein said secondforce created by said roller band varies inversely to thecross-sectional area of said tapered segment of said roller band whichis in operable engagement with said indicator means.
 7. The bathroomscale of claim 6 wherein said cross-sectional area of said depressedsegment of said roller band which is in operable engagement with saidindicator means comprises a uniform cross-sectional area when said loadis removed from said platform.
 8. The bathroom scale of claim 7 whereinsaid roller band comprises a flexible steel band.
 9. The bathroom scaleof claim 7 wherein said roller band comprises a flexible plastic band.10. The bathroom scale of claim 8 wherein said depressed segment isformed by chemically milling said surface of said roller band.
 11. Abathroom scale comprising: a base member; a platform member mounted forfree vertical movement relative to said base member; a first memberoperably connected between said platform and said base, said firstmember being adapted to convert said vertical movement of said platformto a torsional force in response to a load placed thereon; a lever meansrotatably connected to said first member and operable in response tosaid torsional force; a second rotatable member operably connectedbetween said base and said platform; a third rotatable member operablyconnected between said base and said platform, said third rotatablemember being positioned adjacent to said second rotatable member; aflexible roller band having a first end and a second end, said first andsecond ends being secured to said lever means and wherein said rollerband is looped in a generally S-shaped fashion about said second andthird rotatable members; and indicator means rotatably connected to saidthird rotatable member for indicating the weight of said load whereinmovement of said lever means in response to said torsional force causesa rolling movemenT of said roller band thereby producing a second forcein opposition to said torsional force and wherein said second forceproduces rotation of said indicator means.
 12. The bathroom scale ofclaim 11 wherein said roller band comprises a depressed segment having atapered cross-sectional area wherein said second force created by saidroller band varies inversely to the cross-sectional area of said segmentwhich is in operable engagement with said third rotatable member, saidsecond force being indicative of said load on said platform and whereinthe movement of said rolling band thereby causes the rotation of saidthird rotatable member.
 13. The bathroom scale of claim 12 wherein thediameter of said second rotatable member is greater than the diameter ofsaid third rotatable member.
 14. The bathroom scale of claim 13 whereinsaid first member comprises a ball screw and nut.
 15. The bathroom scaleof claim 14 wherein said roller band comprises a flexible steel band.16. A bathroom scale comprising: a base member; a platform membermounted for free vertical movement relative to said base member; a ballscrew and nut operably connected between said platform and said base,said ball screw and nut being adapted to convert said vertical movementof said platform to a torsional force in response to a load placedthereon; a lever means rotatably connected to said nut and operable inresponse to said torsional force; a first rotatable member operablyconnected between said base and said platform; a second rotatable memberhaving a diameter smaller than the diameter of said first rotatablemember operably connected between said base and said platform, saidsecond rotatable member being positioned adjacent to said firstrotatable member; a flexible steel roller band having a first end and asecond end, said first and second ends being secured to said lever meansand wherein said roller band is looped in a generally S-shaped fashionabout said first and second rotatable members, said roller bandcomprising a depressed segment having a tapered cross-sectional area;and indicator means rotatably connected to said second rotatable memberfor indicating the weight of said load wherein movement of said levermeans in response to said torsional force causes a rolling movement ofsaid roller band thereby producing a second force in opposition to saidtorsional force, said second force producing a rotation of saidindicator means and wherein the amount of said rotation of saidindicator means corresponds to the weight of said load and is determinedby the cross-sectional area of said segment which is in operableengagement with said second rotatable member.
 17. A bathroom scalecomprising: a base member; a platform member mounted for movementrelative to said base member; a plurality of adjacent rotatable memberslocated between said platform member and said base member; a guide meansfor guiding the rotation of said rotatable members; a flexible rollerband looped under tension in a general S-shaped fashion about saidrotatable members; transfer means adapted to transfer a load imposedupon said platform member to said roller band thereby causing asubstantially frictionless movement of said roller band wherein saidmovement is indicative of the weight of said load; and indicator meansoperably connected to said roller band for indicating said weight ofsaid load.
 18. The bathroom scale of claim 17 wherein a portion of saidflexible roller band is fastened to said transfer means.
 19. Thebathroom scale of claim 18 wherein said guide means are located in saidtransfer means.
 20. The bathroom scale of claim 19 wherein said transfermeans comprises: a ball screw and nut operably connected between saidplatform member and said base member, said ball screw and nut beingadapted to convert said movement of said platform to a torsional forcein response to a load placed thereon; and a lever means rotatablyconnected to said nut and operable in response to said torsional forceto cause said movement of said roller band.